Elevator-control system.



D. L/XRSON.

ELEVATOR CONTROL SYSTEM. APPLxcATloN HLED JULY 30,1912.

,225,976 Pam-@a May lem.

:Devin Lnnson,

, w y, ai ventenni.

Application filed .'uly 3Q, ll.

Be it known that I, Davie LAnson, a sul)- ject of the King of Sweden,residing at Berlin, in the Province of Brandenburg and.

Kingdom of Prussia, Germany, have inventf ed a new and usefulImprovement in Elevator-Control Systems, of which the following in aspecification.

My invention relates to elevator control l@ systems, and increparticularly to a system et control for automatic alternating currentelectric elevators.

One ci' the objects of my invention is the provision of a simple, cheapand effective system of controlling elevators, and it coni sists in theVarious features of construction. and arrangement of parts having thegeneral Inode of. operation substantially here-- inafter moreparticularly set forth.

Referring to the accompanying drawing', wherein have illustrateddiagranuna-tically a system of control containing an enibodt ment of myinvention, S designates a switch which connects and disconnects thesystem of control and a source of three phase alte).-` vnating currentsupply indicated hy the conf ductors c, Zi and c. An electric motor M isconnected through. suitable inclosed gearing' to a Winding drum G aboutwhich are wound 3o the Galilee' l and 2 connected to the counterbalanceweight lll? and elevatoi ear C, respectively. ifrn electrically operatedbrake lll may be arranged between the motor and the winding drum and thesaine operates to stop the lioisting n'iachinery every time the linecurrent is cut oil from the motor and is released when it is desired tostart the eleva tor. ylhe motor M is here shown as a three phase inotorWhose rotor or secondary winding' is tlo connected through the sliprings 3 which in 'turn are connected to a starting resistance Ri. Thestarting resistance is nornnilly in cir cuit with the rotor Winding ofthe motor when the motor is at rest out .may he varied e5 or graduallyshortcircuited by means of accelerating switches, 4, 5, 6 and 7 toeli'ect the accelerating of the motor to full running' speed. Three ofthe accelerating switches are substantially the saine in construction.

the last one designated by 7 comprising' in addition to its resistancecontrolling contacts a dashpot 7 which retards its closing' action andan insulated contact l) which is adapted to pass over and make Contactwith a series @timed contacts, i0, vlll enel l2? which Specification ofLetters Patent.

connected to the :magnet windings of the accelerating switches 4, 5 andC, respectively. The direction of rotation of the motor is controlled bymeans of the reversing switches ll and l), which are similar in,construction 3o and operate 'to interchange or reverse the inain lineconnections and c, the middle main being' connected directly to thestator winding of the motor. il. circuit closing switch lo controls theinain line circuit to o the motor and the saine oper-etes only after thereversing' switches have first established the proper motor connections,so that the inotor will rotate in the desired direction when its circuitis closed to the main line at '7G the contacts of the switch L, rEhereversing switches 'U and l) are provided with noninterterence contacts,257.26 and 27. 28, respectively', which are always in closed circuitrelation when both of the switches are de- 7 energized, hut will operateto prevent a false operation when the coi'itrolling' system is inoiieration. At each floor landing is a push button, 29, 30, 3l and 32,also a, door contact 33, the latter being closed whenever the 8correspiinding door is closed and vice versa. The elevator car C has aseries of push but tons, 34, each button corresponding to a licorlanding, and the car also contains a stoy button and ear Contact 3G. Hdesin` 55 nales a. floor controller, and while the saine may lie ci? anyde 'red type of which there are several, l prefer to employ the oneshown diagrmnnialically on the drawing, which similar to that shown anddescribed in pat- -f ent to (lariclioi'l, 783,174-, February 2l. 1905,system of electrical control. This `controller comprises a series oiLcani operated circuit controlling switches, 5G and el?. i'lfhich areoperated hy a corresponding serie.' oi rotat- 95 ingr arms geared tosome moving part ot the hoisting machinery, such the drum :shait forinstance, and moving in synchronisni with the elevator car. Similarswitches. 57

and 5S are normally closed and only operate l0( at the liinits of cartravel. There are lloor relays, 5G, 5l, 52 and 53, corresponding' to thepush buttons in the car and at the various iloor landings, There is alsoa non-iui'eriereuee magnet S7. comprising' double 105 wound coils, 38and 39. and an armal ure 41,

(a. ming a. pair o con a( ,a 1 ne 4... ai.

Llf3 ie: normally in electrical engagen ned contact lil, Ywhile theconcontact, 40 l l' car when the latter overruns its norma 6," fwhich iscommon to all of @clays` through the slack cable switch 59 il Y1,225,9'7@

when 'the magnet 237 is energized, A slack cable switch, 59, and limit sw'itces 61 and 62, are arranged toward the top and bottom of thehatciiway and are operated bfxthc nnits of travel in either direction. Agovernor switch 60, normally iir closed position, is shown, but whichwill-open to interrupt the operating circuit Whenever the car attains enexcessive speed Having described the parts of the a paratus, I willpoint ont the operation o the system. Assuming the car to be at restoposite the second Hoor landing, -as shown, liat it be supposed that apassenger on the third Hoor landing desires to use the elovator car.Uponv pushing the button 3l a circuit is established to thevioor relay5'?, which circuit ma)y be traced from the main c, through the wire (i3,contacts .218 and 2li of the respective reversing switches l) and U,resistance 45, contacts and 44 of the non-interference magnet switch 37,wire Gel, which is common to all of the floor landing buttons, throughthe push button 31, wire 6,5, winding ot' relay 52, and hv the wire thefloor and. to the main a. The relay 52, with thc resistance 45 in serieswith it, is now con nected 'across the mains c and a, and the relaywill'at once operate to close its contacts 54, thereby establishing acircuit through the iioor controller H and the magnet of the reversingswitch U. This latter circuit may be traced from the main a, through theconductor 66, relay 52, relay contacts 54, contacts 48, 47 and 49, ofthe floor controller, contacts of switch 57, coutacts 27, the magnetwinding of the reversing switch U, wire 67,-door contacts in serles, cargate contact 36, contacts of stop switch 35, and by thewire'GS to themain b. The closing of l,the Vrelay contacts 54 establishes a selfholding circuit for this relay and for the magnet winding of thereversing switch U, and the push button 31 may now be released withoutinterruptingr this self holding circuit. The reversing switch U is nowenergized to close its upper contacts 13 and 15, and open the lowercontacts 25 and 9.8, The closing of the contacts 1.3 and lenergizcs thecontacts-20 y switch lli, which circuit may be trucco irom the maine,through the contacts i5 and lil. winding of the switch L, through thelimit switches of. and 6l, governor switch con taci-s GG, tc the mainThe switch L now operates to close its conta-ats 20, Qi, and 15P-22, andthus close nicht: to the stator Winding of the motor M, and the breiteB, and the motor starts at slow speed to raise the elevator ear, itsspeed being limited due to the resistance R being' in the rotor circuitat this time. Upon closing a circuit to the motor and brake, a circuitalso closed to the accelcnatiug magnet i' through the conductors 69 andT0, the latter ronductor being conunon to all of the acceleratingmagnets 4, 5. G and T. Since the ac` celcratingv magnet i" is energized,it starts slowly to raisel its core, this action being retarded by thedashpoi 8, hence it will take an appreciable period ot time before thecontact 9 engages the contar( il). When this does orrur, a circuit isclosed to 'the magnet winding et the accelerating switch 't and theleiter innnmliatelv raits corr l und connected contacts into engagementwith the corresuuuling' stationanxf' contacts directly above to 'shortcircuit a portion of the starting,r resistance an'dallov.' the motor toincrease its speed. .\s the core of the a celeratingr magnet T continuesto rise it successiveliv euergrizes the magnet windings of theacceleratingl switches 5 und (i which operate in turn to short circuitadditional portions of the starting resistance further to increase thespeed of the motor, until finally the accelerating switch 7 has reachedthe limit of its movement closing its upper contacts, whereupon all ofthe starting resistanre will be short circuiicd andthe motor will havereached full running speed with short circuitcd rotor. t

Tt will 'be observed that the contact 9 in passin, r over thestationar)v contacts l0, 1l and l2.'mal{es contact with one of thecontacts such as 'll before it leaves the contact 10 next to it. Thuswhen the accelerating magnet 7 operates, the resistance R is gradullyshort-circuited by the magnets 4, 5, 6 and T, and furthermore. when themagnet 7 has reached the limit of its movement in an upward direction,the Contact 9 has been carried out of engagement with all of thecontacts 10, 11 and 12, and the magnet alone remains energized. rlhismethod of operation effects a considerable saving in current consumptionand prevents the accelerating magnets l, and 6 from becoming over@heated since they are only momentarily energized. i

In order to guard against any possible interference from'anothcr iloorpush button, l have provided thc non-interference contacts 26 and 2S outhe reversing switches, and it willbe observed that as soon as one ofthe reversing switches such as U starts to move, and before it hasclosed its upper contacts, the contacts 20 will be separated,l

iso

ivonlri very soon over-heet und iernege the motor. f

like operation of lie System for e de.- seenriiw elevator ear is similarto that el ready n seribecl, tlie lioor controller.1 eireuits being suchthat the reversing switch D Wil] be energized inst-enel of the reversingswitch U :is `before. The lower 'contacts 28 and 27 of the switch Deffect the same or similar re'- eults :is the Contacts 26 and Q5respectively of the switch U., to prevent interferenee from the 'pushbuttons and to prevent the simultaneous operation of the reversingswitches.

In emmeetion with the non-interference magnet 37, it 'will be noted thatit performs time double function of preventing interference 'from thefloor buttons lifter e car button luis been opereted end the enr is inmotion, :1nd also to prevent such interferenee even after the cer hascome to rest at the designated Hoor landing; thus after the enr luiscome to rest the passenger must first leave the enr :mil eiosc -tlie enrgate )nid inmlingi: door :ifl'er liini iwiore it is possible to obtaineontrol of the eievntor eer from combination of uvpolyphase supplycircuit,

en alternating current motor, n magnet controlled reversing switch forthe motor, n magnet controlled main line switch for the motor, a relaycontrollin the reversing switch, and e push button lor o ernting therelay, the operating magnets o. the reversing switch, mein line switchund relay bcing connected in u different phase of the snpply circuit.

In testimony whereof, I have signed my nume to this specification in thepresence of two subscribing witnesses.

DAVID LARSON. Witnesses I llnNm ll'Asi'nrc, v/vormen An ll A U1 "r.

